Many of the most fascinating events in the kitchen garden take place underground, away from the eyes of the gardener. Germination and root development are best left undisturbed, as are the earthworms that work tirelessly to improve our soil. If you grow root crops and tubers then you may have some idea of how well the plants are doing through the summer, but it’s only when it’s time to dig up the crop in the autumn that the true picture is revealed. The joy of digging up your own potatoes never diminishes, but there are other tubers you can try that are more unusual.
Jerusalem artichokes (Helianthus tuberosus) are rapidly becoming one of my favourite kitchen garden crops. They are such easy-to-grow plants and the tubers are delicious. Not only that, but they come at a time of year when there is very little growing – their natural harvest time is from the first frosts until late winter. Planting half a dozen tubers will produce a respectable harvest, even under less than ideal conditions, and you can even plant Jerusalem artichokes in containers.
I’m hoping that Chinese artichokes (Stachys affinis) will be equally easy and tasty. Known as Crosnes in French, Chinese artichokes are far more attractive than Jerusalem artichokes, although they look just as fiddly to clean. Apparently they are more likely to flower and if you establish a permanent bed they will grow on year after year from the tubers you don’t manage to dig up.
If you’ve got a sweet tooth then you might like try Tiger nuts, also known as chufa. Cyperus esculentus is a member of the Sedge family, a grassy looking plant that is related to papyrus. Tiger nuts were used as a substitute for sweets in the Second World War when sugar was rationed, and are available from some health food stores. They’re also used as carp bait!
Tiger nuts thrive in damp areas and also in containers. Although the tubers are small you can grow a reasonable crop. Tiger nuts may never become a mainstay in your diet, but they’re an attractive plant to grow and very vigorous.
I have already ordered my Oca (Oxalis tuberosa) tubers for next year. Oca is one of the Lost Crops of the Incas, grown in antiquity and still popular in the Andean region today. Oca needs a long season to grow and so, in the UK at least, will need some protection at the end of the summer to protect it from frosts.
Oca tubers are very colourful and used like salad potatoes – lightly boiled or deep-fried – although they can also be eaten raw. They have a slightly lemony flavour, and because they aren’t affected by potato blight they could well become more popular in the future.
Another Andean favourite, with the ability to store for winter use, is Mashua, also known as Añu (Tropaeolum tuberosum). This is even more exotic that Oca and Chinese artichokes and you may be hard-pressed to find some tubers to sow. The only person I know who has grown it is Patrick from Bifurcated Carrots.
Añu tubers are eaten cooked, and the leaves and flowers are edible too – with a flavour similar to that of the flowering nasturtium we’re all so familiar with. This is a climbing plant, so it will need to be given some support.
These are just a few of the interesting tubers that you could grow in your kitchen garden. There are plenty more, so I will come back to this subject another time.